Genistein is an isoflavone found abundantly in soy products and other plants. Genistein has been reported to have beneficial effects in preventing cardiovascular disorders, hormone-related disorders, and cancers ([1-5]). Genistein has also been reported to induce apoptosis and inhibit activation of NF-kappaB and Akt signaling pathways ([6-8]), act as an antioxidant ([9, 10]), manifest biological effects through interaction with the estrogen receptor ([7, 11]), and inhibit protein tyrosine kinase ([12, 13]) and cellular proliferation in vascular endothelium and smooth muscle ([14, 15]). In addition, genistein has been found to stimulate insulin secretion in pancreatic beta cells through a cAMP-mediated protein kinase pathway ([16]), suggesting involvement of genistein in metabolic processes. Incubation of genistein with endothelial cells has also been reported to result in the accumulation of intracellular cAMP and to lead to activation of cAMP-dependent protein kinase A ([17]). Involvement of genistein in metabolic processes has also been implied in a publication reporting the regulation of leptin secretion from adipocytes by genistein ([18]).
Diphenyleneiodonium Cl is known as a potent and irreversible inhibitor of NO synthase (NOS). It has been shown to inhibit NOS in cultured peritoneal macrophages (IC50=30 nM), as well as block acetylcholine-induced relaxation of rabbit aortic rings (IC50=0.3 μM) ([40]). It also inhibits other NADPH-utilizing flavoproteins such as NADPH oxidase of human neutrophils ([41]) and macrophages ([42]). Diphenyleneiodonium Cl has the following structure:

Sanguinarine is an alkaloid obtained from the bloodroot plant, Sanguinaria canadensis, which is used to treat and remove dental plaque. Sanguinarine is known to have anti-microbial, anti-inflammatory and anti-oxidant properties. It also has anti-proliferative, pro-apoptosis effects in some cancer cell lines ([43, 44, 45, 46]). Sanguinarine Cl has the following structure:

The sanguinarine family of plant alkaloids also includes structurally related amphipathic cations such as berberine and palmatine.
G protein-coupled receptors (“GPCRs”) are a family of cell surface receptors that upon activation by their endogenous ligands transmit extracellular signal into cells to control a variety of cellular functions. The most commonly recognized signaling transduction pathways are those mediated by the G protein families including Gq, Gs, Gi, and Go. Recently other pathways independent of G proteins are also found such as beta-arrestin-mediated signal transduction.
GPR78 has been cloned and found to be expressed mainly in pituitary and placenta ([19]), and has been implicated in a genetic linkage study in bipolar affective disorder and schizophrenia ([20]). There have been no reports on the identification of ligands for GPR78 to date.
GPR78 has also cloned and found to be expressed mainly in the brain. There have been no reports on the identification of ligands for GPR26 to date.